Field of the Invention
The present application relates to etching processes, more particularly to thermal atomic layer etching processes using sequential reactions.
Description
Vapor deposition processes such as atomic layer deposition (ALD) are well-known. ALD processes typically utilize alternating and sequential pulses of vapor-phase reactants to deposit up to a monolayer of material in a controlled and highly-conformal manner. Thin films deposited by ALD are used in a wide variety of applications, such as in the formation of integrated circuits. Controlled removal of materials is also highly desirable. In contrast to ALD, atomic layer etching (ALE) utilizes sequential pulses of vapor phase reactants to remove material from a substrate in each reaction cycle. Typical ALE processes utilize a first reactant to form a first species on the substrate surface that is then removed by a second, excited species generated from a plasma.